Raised Hugelkultur Bed on Limestone Shelf in Central Texas

After seeing the subject of this post, you may be going, "Why - oh why, - oh why?"

I am wondering if anyone can share their experience in this type of climate going with Hugelkultur raised beds on a limestone shelf. If not, what did you use (on a limestone shelf in a similar climate)? If nothing else, maybe I can report back on this experiment's outcome.

I have a situation where I want to use all natural materials (no man made structures) on a limestone shelf and also near the front of the property/visible to passers by. See the photos and video below for more visual details.

Long of the short, it generally sounds like other options like berm and swale, may be more suited for the conditions. However, with the materials I have available and the limestone on which I am considering building this, I was thinking might as well try hk. If using the hk raised bed, I'm interested in any tip refinements for getting some water retention in the building stage. I've read and watched videos on the Hugelkultur article Paul crafted so well. However, I'd be interested in others in Central Texas or similar climates as to small refinements on the creation of the bed to keep more water. For instance, should I do the logs with mulch and water very well, then cover with soil, water very well, then more mulch and more water? Since I am considering a raised bed in this climate...would anything help? What about to help break down the wood? I saw mention of termites somewhere. I'd also think adding mycelium may be an option...or not in our climate.

My husband and I have put in the first layer of logs, but there is still time for us to change direction if something else sounds more suitable.


LAND PROFILE

Zone 8b;
latitude/longitude of 30° 16' 0" N / 97° 44' 34" W;
average rainfall of around 33";
average first and last freeze of 11/27 and 3/4
soil profile: the area for the hk raised bed: limestone shelf. USDA web soil survey has for that and surrounding area "Brackett-Rock outcrop-Comfort complex, 1 to 8 percent slopes"


THE WHY

I want things on the limestone shelf primarily to:

1. Act as a barrier from street viewing into our property (natural privacy fence). This is in part for our human desire for more aesthetic interest and also additional privacy; see photos and video below. Also, we'd like to add more visual interest and more flowers for our bees and other beneficial insects and small reptiles. If we can make it work on a limestone shelf, we'd like to add Flaming Sumac, among other options.

2. We also plan to move the ducks up to this area of our 5-acre property. While not right next to the Hugelkultur bed (80-ish ft. from road), the duck pen would be about 150 ft. from the road. As such, we want to block to some degree sound, noise, and visual intrusions from the road to our ducks. We also want to have fragrance enhancers/odor barriers and visual blocks from our ducks to the road. We are on a sloped piece of property, so we want to build the hk raised bed on the higher point to give more of a barrier.


THE VISUALS

Zoomed in area


Zoomed in area, with contours and notes. The proposed bed is on the lower left hand side of the image.


Note that this is a preliminary stage, and, obviously, the hk structure is not yet complete. I'm going to have to ask you to bear with the video formatting. I should have turned my iPhone sideways to film, but I'm on crutches now (not b/c of Hugelkultur!), so I am not going to be redoing those wonky parts. Thanks for your understanding




BACKGROUND AND MY ASSUMPTIONS

I read a lot on these forums, but there were still many more posts I could read. Thanks so much for everyone who has posted his/her experiences and questions. Basically, the takeaway I have is - and feel free to correct me if I missed something:

1) There aren't a lot of examples of Hugelkultur in arid environments without a lot of regular watering as input.

2) Most of the hk's are in the ground to help with evaporation issues.

On this forum, I especially noted:

https://permies.com/forums/posts/list/40/12150?OWASP_CSRFTOKEN=Z165-Y8T5-R9YL-K28H-7CT4-3FS1-LHJ2-M5V1#144371
(Abe and Tyler's discussions in particular)

https://permies.com/forums/posts/list/80/12150
(Marsha Hanzi's observations)


THANKS FOR YOUR INPUT!

I was so sure when I saw that I got my first apple for a post (!!) that surely I'd get lots of replies. Well....durn...

So let's change the question and parameters a little. I am going forward implementing this HK design. I noted in forums people saying there is very little documentation on HK in arid environments. What metrics would people like to see collected? What is the control in such an experiment, and what is it compared to? Compare to other garden installs in other parts of my land? Compare to HKs in other climates?

The measurements I plan on for certain is:

1. Initial size of HK bed (L/W/H)

2. Soil pH at different depths

3. Amount of water used to maintain the bed.

4. Changes on 6 month basis.

Input welcome.


Other ideas?

Hang in there Michelle, some times it takes a while for folks to get in out of the garden and get on the computer. Great post by the way!

Thanks, Miles. I did get a Purple Mooseage back from someone in Central Texas who had done some above ground hk beds. As I ask more people in my area and can actually go see their beds, it seems that the response below is not uncommon. The HK beds, especially compared to berms/swales, survive but do not thrive here in our hotter, drier climates. Maybe I should move this post to another forum posed as a "What natural building materials would work best in this situation?"

We'll see if anyone adds any more feedback over the next week or so. I also will review Ch. 11 of the Mollison manual to see if any eureka moments strike.

The response from someone on this forum who had photos posted on this site of raised hugelkultur beds:

Well that hugelbed is two years old now and although the Mt. Laurals are still alive, they are not thriving. I think the problem I have with them is we can't afford to buy soil to cover the logs properly, so now there are gaps and I'm sure critters have helped with that problem too. The beds dry out and are tough to water them completely.

Last fall I made a hybrid huglebed for my blackberry plants, but this time I cemented rocks together to make the side walls then filled with dead oak trees, soil, compost and topped off with mulch. That bed was doing fine until last month when it really started to dry out and now I have to water it just to keep the berry plants alive. I'm hoping this winter to add more compost (have too because it's sinking) lave sand, and bio-char so that next year we get a real crop of berries.

In January I made a huglebed for my asparagus and it too is now showing signs of sinking and drying out. Same with my strawberry bed. I planted bush beans along the lower edges while the strawberry plants get established, and those beans went crazy with hardy any attention from me. But here we are in hot, dry August and that bed needs watering every other day to keep the berry plants alive in the heat.

So to sum it up, I'm on the fence about if using dead trees limbs actually helps lower the amount I have to water or not. It could be that because everything I planted did fine on it's own for so many months that I didn't keep a good enough eye on them once the summer heat hit and the rains stopped. Now that the soil is so dried out, it takes so much more to get it rehydrated.

Hi Michelle! IDK how much help I can be, but it seems to me that in an arid climate, if you want to grow veggies, you're going to have to supply quite a bit of water. Less with the HK sure, but water you will... I built what I call a semi-Hugel raised bed. It's made of 8" concrete blocks laid up dry, with some metal rods between the walls every 4' or so, to keep it straight. I also filled some cores with cement. Put in a mixture of shredded tree trimmings and old rotten wood just laying around. Put topsoil, sand, and compost (well-mixed) in the top 8" for a growing medium. Seems to work OK, but demands more water than ground level plots.... Good luck to you! Remember, gardening is a whole lot like being a Cubs fan, "Wait 'till next year!" Best, TM

Thanks, Tim.

I appreciate your feedback. I was watching a 1994-95 Permaculture Lecture Series Bill Mollison gave in Texas and he mentioned arenados (sp?), so I'm going to check more on that. Basically, it sounds like stones and gravel with some soil, which would work well with natural building materials in my criteria set for this part of the property; I'll need to research a little more first. I still have to watch Mollison's talks from 94-95 on Drylands and still review Ch. 11 of the PDC manual. I have other parts of the property where I'll concentrate more on higher food production and may use wicking beds and/or berms and swales there. I'm interested primarily in screening/privacy and fragrance in this particular spot, with food as a secondary bonus. I'd like trees where possible.

Maybe tonight is a good night to watch more of that 94-95 Mollison series.

tbc...

I live in N central TX , its really too dry for the east coast type hugle culture ,Texas oak is tough ! burying wood speeds up rotting but fire ants and termites move in by the droves , wood here where I live does not rot down easily it is eaten by bugs , I chip near everything chipable and mulch with it .

Hi, Michelle. I live east of Elgin, but used to live in Dripping Springs so I'm very familiar with your soil (or lack thereof) problems. We have been making hugel beds for 2 years now as a way to deal with all the dead oaks from the drought, and also as a way to make organic matter to compensate for the sandy soil (part of the Lost Pines). Getting and keeping the beds hydrated is definitely an issue, but my oldest bed seems to have finally turned the corner. Someone mentioned to me that adding straw might help, so I'm going to try that on the next bed. I have also noticed fire ants moving in on occasion, but fire ants are a fact of life with or without hugelkultur. (I just pay attention when I first start digging in an area). That may also be due to a lack of other critters in the soil. My initial excitement has been tempered somewhat, and I agree that blindly accepting this will work in a semi-arid climate is naive. What seems to work best is combining hugelkultur with swales on contour just upslope of the hugel bed to capture runoff and force it into the wood. My first beds were not oriented that way.

Hi Michelle,

I too live in limestone land! I have had success with a keyhole garden - I built it all with free / found materials. It's basically a hugel on the bottom with growing medium on top and a composting basket in the middle. From the top, it looks like a doughnut with a wedge cut out.

Texas Co-op Power(where I first discovered it)
Building a Composting Keyhole Garden
Keyhole Garden 6 month update

If you decide to do something like this, you can position the cut so that it can't be seen from the road. I can see that putting compost in something not so close to your house may make this an undesirable option. The also get really hot in the beginning, like all hugels, as it decomposes. I had some really hot spots in mine where nothing would grow - soil temps reached almost 100 degress F.

Good luck with your projects!

Thanks, Diogenese, Betty, and A.M., for sharing your thoughts. Betty, I am especially interested in hearing how your HK experience progresses!

I finally DID finish the first part of this project! I really could see the value of having had a trailer or a tractor with a bucket, but nothing that couldn't be handled with slow and steady progress. We just finished Sunday, and we are supposed to potentially get flash floods starting tonight, so I want to post all the photos after the rains to see how things hold up. I'll probably post within this coming week.

Stay tuned!

I have been meaning to post photos. For now, let me just note that the HK bed ended up at 18 ft. L x 8 ft. W x 3 ft. H, using Geo Growers' Berm Builder. Remember, I was on limestone and needed soil. There comes a point of tradeoff from research and analysis to trial and error. I'll still probably add some buffer (rocks or branches) on the "back" side for establishment as an exterior wind buffer. Truthfully, maybe another building technique would work better here, but let me try and see what I can glean.


Preliminary pile, naked:



Berm Builder:






Completed berm, with cedar log skirt up downslope side. I'll probably come back and add rocks, mulch, or other on this side.


A few weeks later (after 2 sizable rains):

Hey Michelle, in the picture after the rains it looks like everything washed away? Or is that still just berm mix? What did you plant in it?

Hi, A.M.,

No, everything stayed intact in berm builder. I just zoomed in to show the cover crops growing on the top part of the berm. I planted a mix of hairy vetch, clover, and some other stuff. Maybe that's the clover coming up? I'd go edit the caption on the photo in the last post, but I don't have an edit button on that posting. hmmm...

I'll post another photo when I get a chance.

Here are those pictures after the rain. The photo of the small green growings was a zoom-in. The bed is still there. I planted Mexican Mint Marigold yesterday near the base on one side yesterday...but I didn't get photos yet.

I will be trying near Burnet, Tx. I am planning to use round bales, add all the stuff on top, and leave it alone. I am hoping to get it started before spring so that it's natural watered. We bought an severly overgrazed plot of land, so first few years will be building it back. Much of the land is a slope, an the water just rushed off.

My brother has a farm on karst in the Yucatan peninsula of Mexico. He grows deep-rooted perennials and uses plenty of mulch in thick patches. Most annuals are more trouble than they're worth in his situation.

Hi Michelle,

I put in a small Hugel similar to yours out here in Oak Hill last year. I used old logs from my yard and my Dad's property in Dripping - mostly live oak. It did pretty well for the first year and now in the second year I think it's even better. I am lengthening the bed to create a swale that will capture some runoff when it rains to help instill more water into the bed.

Mine is not on a shelf per se, but it is on really rocky ground downhill from the house. There is some soil mixed with limestone "plates" and gravel, but I add turkey compost to beef it up. I dig (read pickaxe) down about 6" and then add the logs, screened soil and compost. I stack more logs to end up with a bed about the same height as yours. I also have some drip irrigation lines across the top of the Hugel to keep things moist when it really gets dry. I don't think this can be avoided, but it certainly was better than a plain old raised bed sans wood. I did mulch with shredded Oak leaves and some grass clippings to help keep the soil in place. I feel like the soil moisture was more constant last summer due to the wood holding water. The tomatoes and peppers were happy - I made lots of salsa!

Thanks, Jt Franklin, for your response. It's good to hear what other folks are doing in this same area. I am betting we are about 10-15 minutes from each other's places. I finally took and uploaded some updated photos of the bed. Because of the wet past few months, I haven't had to irrigate it at all. However, I think your strategy to have drip irrigation is wise. I also have an olla I'd like to put in this bed. Let me post those photos...

From 12/5/2014 and then from 4/4/2015:


We added a garden fence in March. The HK bed is outside the fence.



Some other photos...

1. We planted a couple of Texas Torchwood on the bed on 3/15/2015. I pulled back the hairy vetch a bit from around those areas when they started overtaking the young trees.



2. Hairy vetch on the mound. It definitely has held up to being deer resistant!

Hmm...I'm not sure why some of the Flickr photo are now showing as "not available". They are still there. Let's try posting the before/after photos again:

Michelle, I'm super excited for your progress. I'm still new to HK beds and I also live in a much more wet climate. However, I believe you're on the right track and just need to wait till the wood material breaks down enough to be a good sponge. Remember that you can always continue to amend the berm with more mulch as time progresses. I would recommend wood mulch and compost. Layer that like a lasagna garden and a good soil inoculant would definitely help, especially to start breaking down your wood material. There are definitely some conflicting info on the net but adding phosphorus to the soil, either by amendment such as bone meal, or by using plants who naturally pull phosphorus from the deep soil and leave it in a form readily available to other plants. Phosphorus is said to help plants build deep roots. The better the root system and mycelium, the better the water retention of the soil. Anyhoo, good luck and keep up the faith and hard work!

Here are some more updates since my last post. This has been a comparatively lush year to date in terms of rainfall. My HK bed would be fine (to date) without drip irrigation. However, I am planning for the usual Central Texas summers and rainfall totals that will inevitably come.

This was the same bed on 5/10. We are adding drip irrigation lines on top in preparation for inevitable high summer temps and low rainfall that will come, whether this year or another.



You can see the remnants of the hairy vetch cover crop pods here:



The Mexican Mint Marigold that my dogs insisted needed to come out of the landscape made it through their multiple excavation exercises!



Texas Torchwood with some organic corn I'd thrown out on this mound coming up.



Old hay we used to cover the drip irrigation and mound:



Mound covered with hay. Cover crop seeds spread before hay placed on mound.


Then we had rain, day and night for the next week (it's still going on). In 4 days, the first buckwheat cover crops emerge all over the mound.

Thank you for the update!!! Your berm is looking good!!! It's crazy how quickly some seeds will sprout. Did you look into soil inoculants? That could help create a healthier root system and help to break down the woody material. Again, looking amazing. I'm planting Russian comfrey and crimson clover today in my HK project. Good luck!

Good looking hugel. You are doing all the right things so now it is just continue along the path and reap the rewards. Good idea to cover with the hay, once that decomposes and if you add more each year, you will end up with very nice soil for crop growing.

I am a Permie Wanna Be; to be clear, I don't know much about Permaculture. That said, I would appreciate advice and direction.

Eight years ago, I bought a little 10 acre place in Mariposa, California with the idea that I would someday retire there. Mariposa is next to Yosemite; we have a lot of granite. There is a corner I would like to convert into a garden, but it looks the same today as it did 8 years ago; it's solid granite. It's a triangular shape, roughly 100' x 100' x 100'. I wondered if it would be a good spot to put in a Hugelkultur based garden.

We have been in a drought, so we have plenty of dying of pines and oaks.

I would appreciate thoughts on what might be done on this spot.

Mariposa received ~30 inches of rain this year, so perhaps the drought will be less of an issue going forward.

Thanks.

Claudia,
In an area that size I would consider a sheet mulch instead of a straight hugelkulture. The added surface area of the hugels can be a detriment during those hot dry summers....just a thought.

Claudia Smith wrote:I am a Permie Wanna Be; to be clear, I don't know much about Permaculture. That said, I would appreciate advice and direction.

Eight years ago, I bought a little 10 acre place in Mariposa, California with the idea that I would someday retire there. Mariposa is next to Yosemite; we have a lot of granite. There is a corner I would like to convert into a garden, but it looks the same today as it did 8 years ago; it's solid granite. It's a triangular shape, roughly 100' x 100' x 100'. I wondered if it would be a good spot to put in a Hugelkultur based garden.

We have been in a drought, so we have plenty of dying of pines and oaks.

I would appreciate thoughts on what might be done on this spot.

Mariposa received ~30 inches of rain this year, so perhaps the drought will be less of an issue going forward.

Thanks.

One possibility I can think of [expensive if you don't have soil SOMEWHERE on the property and the equipment to move it] is building a series of berms moving downhill on contour with an overflow [much how one would build a swale but without the ditch.] With that pure rock you describe, it should be near 100% runoff hydrating those berms. Plant with something drought-hardy, fast-growing and resilient to coppice. Every winter [or autumn, whenever the rains start] fill the inter-berm space with as much small diameter woody material you can get your hands on [either scrapwood from around the property or chop and drop from the berms], and apply some soil overtop this space if you're able to. It's a slow grow method, but I imagine in 5ish years you're likely to have pretty rich soil over that stone at minimal expense [again assuming you have the soil to import to it.]

Livestock [ducks for example] may be able to accelerate this soil building, but would require imported feed which is an expense and hassle.